#include <iostream>
#include <vector>
using namespace std;

int minCostClimbingStairs(vector<int> &cost) {
  int n = cost.size();
  // dp[i] 到达第i个台阶需要的最低费用
  vector<int> dp(n + 1, 0);
  // 初始化 dp数组
  dp[0] = 0;
  dp[1] = 0;
  for (int i = 2; i <= n; ++i) {
    dp[i] = min(dp[i - 2] + cost[i - 2], dp[i - 1] + cost[i - 1]);
  }
  return dp[n];
}

int main() {
  vector<int> a = {10, 15, 20};
  int i = minCostClimbingStairs(a);
  cout << i << endl;

  return 0;
}